Casings for air filters



Sept. 16, 1958 w. s. SAWLE m 2,852,094-

cAsINGs FoR AIR FILTERS I Filed Jan. 22, 1957 1N VENTR.

Unitedy States PatentO i CASINGS FR AIR FILTERS William Stephen Sawle III, Deerfield, lll.

Application January 22, 1957, Serial No. 635,491

15 Claims. (Cl. 18349) The invention relates to air-filters of the type used in air-conditioners.

Servicing air-conditioners which embody fiber-glass, or like lter medium, involves replacement of the parts thereof. In practice, it is desirable to expeditiously make the Areplacements. Air-conditioners of different capacities, shapes, design or make, have a wide diversity of dimensions for tting in or extending across the passages in the housing through which the air is forced. This diversity in dimensions necessitates maintaining for prompt servicing an extensive stock of different sizes or rectangular shapes to tit and service filters in the different passages or conditioners.

One object of the invention is to provide a iilter which is readily variable so that it will fit into and be usable to replace generally rectangular air conditioners of many different dimensions.

Another object of the invention is to provide a filter in which the frame-sections are adjustable and the cross-bars which form a grill are severable to vary their lengths to conform to the width of air passages of different dimenslons.

Another object of the invention is to provide a filter which comprises separable sections of simple construction and which are easily and quickly adapted for installation in structures of different dimensions.

Other objects will appear from the detail description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a plan view of an air filter exemplifying the invention;

Fig. 2 is a section taken on line 2-2 of Fig. l;

Fig. 3 is a perspective view of the end of one of the side-rails;

Fig. 4 is a perspective view of the end-portion of one of the cross-bars; Y

Fig. 5 is an inner side plan View illustrating the bulges on one end of one of the cross-bars; and

Fig. 6 is a plan View of one view of one end of a crossbar and a portion of a side-rail.

The invention is exemplified in a frame or structure for retaining or encasing a filter medium, such as a rectangular mass or panel 10 of fiber-glass and of a suitable area for extending-across a passage in an air-conditioner. In practice, the dimensions of these passages vary for different capacities or are of different widths or heights for structural purposes in different air-conditioners. The filtermass or panel must be replaced when deterioration results from use or the accumulation of dirt and dust. The retaining structure also occasionally requires replacement. On account of the wide diversity of sizes used in air-conditioners of different capacities and in air-conditioners of different structure or designs, in the servicing or maintenance it is advantageous to provide a unit or frame which is readily adapted to be fitted into air-conditioners Patented Sept. 16, 1958 so that it is not necessary to keep in stock a wide range of sizes for prompt servicing or maintenance of the airconditioner.

The lter-mass or panel 10 is rectangular and is retained encased flatwise in a `frame which comprises a pair of mating sections 11 and 12. Each section includes a siderail 13 of angular cross-section with a transverse outer ange 14 and an inward or face-ange 15.

The rails 13 are disposed at opposite sides of the framesections and are provided with the transverse flanges 14 on the outer sides thereof, and face-flanges 15 which are parallel and extend inwardly from the side-flanges 14 at the opposite faces of the frame and in planes spaced apart transversely of the frame to provide a space between the flanges 15 for confining the lter-mass sidewise between the flanges 14 for sidewise conning the mass. Each frame-section also includes a series of' spaced parallel cross-bars 16 having one of their ends integral with the rail 13 at one side of one frame-section and extended across the frame for detachable connection to the rail 14 on the other frame-section at the opposite side of the frame.

The cross-bars 16 onrthe frame-section 11 are xedly attached to the inner face of the ange 15 of that section and extend across the frame for intertting detachable connection with flange 14 of the opposite side-rail on section 12. The cross-bars 16 on frame-section 12 are txedly attached to the inner face of flange 15 of the siderail 14 of the frame-section 12 and extend across the frame for interfitting detachable connection with the side-flange 14 of the opposite side-rail on section 11. The inner faces of the cross-bars engage the outer faces of the filter-mass 10 and are adapted to confine the mass transversely in the having passages of different sizes or widths and heights frame. The side-edges of the filter-mass are confined sidewise between the flanges 14 on the opposite side-rails of the frame-sections.

The connections between the cross-bars 16 and the siderails are adapted to secure the rails different distances apart to conform the flanges 14 of the side-rails to fit around or for filter-masses or sheets of different widths. Each of these connections comprises a series of convex bulges 18 along the sides of one end of each cross-bar 16 which t detachably in sockets 17 in the free edge of a fiange 14 of an adjacent side-rail. Bulges 18 have con- Vex and tapered sides and sockets 17 have concave and tapered sides conformably to and interfitting with the bulges 18 to 'form interlocking and wedging engagement between the bars and the rails for securely and inherently detachably and firmly connecting the bars and rails of the frame-sections together. By transposing the bulges of each series in the sockets 17, the bars of the frame-sections will be extended to secure the side-rails in variably spaced relation sidewise of the frame conformably to lter-masses of different widths. By relative transverse movement of the cross-bars 16 and sockets 17 in flanges and reinserting the different bulges in the sockets in the cross-bars, the sidewise spacing of the rails can be readily varied to fit filter-masses of different widths. The tapered bulges 18 have a wedge t into the sockets 17 and tightly and irictionally secure the cross-bars in the rails and to positively interlock the cross-bars and rails in assigned sidewise spaced relation. The convex bulges permit rather slight adjustment of the cross-bars in the rails. The housing of the air-conditioner usually contines the frame-sections against transverse separation.

The sections of the frame are each integrally formed in entirety of suitable plastic, such as. polystyrene, so that each section has integral side-rails, cross-bars and extensible interfitting connections. The ends of the crossbars which project from the outer sides of the rails when they are contracted to fit around a filter-mass of relatively narrow width, may be readily severed between the bulges and from the bars respectively when-made ofsuch-plastic material. The bars 16 may be calibrated as at 20 to guide the worker in placing the cross-bars at the desired sidewise Y spaein g. VThe "rails, being ferin'ed f pl-astio, are also severable at their ends fforredticirig -or vary-ing lthe length of the frame to fit filter-masses of diferent-lengths The -onter races of the# opposite #ends et "the side-'rails maybe calibratedlas at-`21`to guide the-worker in severing them conformably tol thelter-mass.

ln/pr'actice, Vthefrarne-unit -is-furnishedwith bars Het suiiicient length'andrails of suiiicientheight for iiltcrs having a range'of different'widthsfaum:heightsI `vWhen the sections xare-assembled, the cross-bars-frm'aretaining grillforfilter medium. 'To tit the'fra'rneeunit in airconditioners of narrower width, the bulges 18ct tliefends of thecrossLbars areinterittedwith4 s'ockets'so that the side-railswill space sideLrailssid'ewise 'to' conform to the narrow lter-mass `andso its' edges will fit between flanges 14. The bulgesatthe ends'of thev cross-bars 16 which project from the outer sides'bf the Vside-rails will be severed from the cross-bars which are 'integral'with the opposite side-rails, preferably on the narrower v'zones betweensaid bulges.

When' the' frame-sections 'are' separated transversely the filter-mass can be readily placed between the cross-'bars 16, andside'vvise 'between 'the tian'ges 1'4 of the side-rails. When the frame-sections re'then Vsecuredtogether by locking the bulges 18 at the opposite ends of'said bars in the adjacent 'side-rails the'proje'cting ends of the crossbarsmay be severedthrefrom.

When it is desired tot the frame to an air-conditioner of lessheight, the'ends of'the side-'rails may be severed to Vreduce their height for Vconformably to the shorter lter-mass, as guided Vby the calibrations Zi and this severing may include one or more cross-bars if necessary. The rails being ot plastic, are easily severableby a. suitable cutting tool for this purpose.

The invention exemplifies a frame for an air lter which is formed of sections with integral cross-bars which are readily adapted to secure the rails in dierent sidewise spacing for lters of different widths, and siderails which are sever-able for filters of different heights. The sections are formed of integralparts and can be produced at a low cost.

The invention is not to be understood as restricted to the details set forth since these may be modified within the scope of the appended-claims without departing from the spirit and scope '0f-the invention.

Having, thus described theinventionwhat l claim as new anddesire to securev by Letters Patentiis:

l.V A substantially rectangular frame for replaceably vretaining Aa tilter mass, comprising: 'ai pair of! mating frame-sections including rails at opposite sides, respectively, a 'series of. cross-bars havingl one end iixedly secured toonc Vof fthe-"rails, ay secondV series of cross-bars having oneiof their'ends secured'to the opposite siderail, and detachably intertitting means between ythe opposite ends-:of the bars'ofthe series and the'adjacent'rails, respectively, for securing the rails 'spaced apart sidewise conformably to masses of dilerent widthsgthe series of bars being transversely spacedapart'and forming a' grill for confining the mass betweenthem. Y

2. A substantially rectangulariramelfor `retaining a filter-mass, comprising: a pair of'mating` frame-'sections including` rails at opposite sides."respectively,`aseries ot cross-bars having one end'integral with oneof'the rails, a second series ot' cross-bars'having one of their ends integral with vthe opposite side-rail, the bars forming a grill for the'mass, and detachably intertting means betweenV the opposite ends of the bars of the series and thc adjacent rails, respectively, for securing the rails spaced apart sidewise conformably to masses of different widths, the series of bars being transversely spaced apart and forming a grill for conning the mass between them, the

ends of the bars being severable conformably to the sidewise spacing ofthe rails.

3. A substantially rectangular retaining frame for a filter mass, comprising: a pair of mating frame-sections of plastic material including rails forming opposite frame sides, respectively, a series of cross-bars having one end integral with one of thefrailspa second series of crossbars having one of their ends integral with the opposite side-rail, the bar-s forming aV grill for said-medium, and dcachablyintertting means between the opposite ends of the bars oi each series and the adjacent rails, respectively, for securing the rails spaced apart sidewise con- Eormably to masses of different widths, the series of bars being transversely spaced apart for conlining the mass between them, the ends of the bars being severablc conformably to the sidewise spacing of the rails.

4. A substantially rectangular retaining frame for a Filter mass, comprising: VapairV offmatingframe-sections of plastic material including rails forming opposite frame sides, respectively, aseries of cross-bars-havingone end integral with one of the rails,a second series-of cross-Y bars'having one of their ends integral with the opposite side-rail, the bars forming a grill for said medium, and detachably interlitting means between the opposite ends ot' the bars of each series and the adjacent rails, respectively, for'securingthe rails spaced apart sidewise conf-ormablyV to masses of different widths, the series-"of barsbeing transversely spaced apart for conii'ning the mass-between them, the ends of the bars being severable conformably to the sidewise spacing of the rails,the' ends of the rails being severable conformably to masses of different lengths.

5. A substantially rectangular frame for retaininga'n air filter-medium, comprising: a pair of mating'framesections havingrails at opposite sides of the frame, respectively, a series of substantially parallel cross-bars having one of their ends xedly secured to one of the rails, a second series of substantially parallel cross-bars olset relatively to the other series having one offtheir ends secured to the opposite side-rail, and-means including detachably intertitting elements between the opposite ends of the bars of both of said series and the adjacent side-rails for securing the rails variably spaced apart sidewise conformably to media of different widths, said bars being spaced'apart transversely and forming a grill for confining the medium between them.

6. A substantially rectangular retaining frame for a filter mass, comprising: a .pair 1of mating frame-sections including rails at opposite sides of the frame,.re'spec tively, of angular cross-section and outer side and inward flanges, a series of cross-bars having one end xedly secured to the inward llange of one of the rails, a second series of cross-bars having one of their ends secured to the inward ange of the opposite side-rail, and detachably interitting means between the opposite ends of the bars of each series and the outer side ilanges of adjacent'rails, respectively, for securing the rails spaced apart `sidewise conformably to masses of different widths, the bars being transversely spaced apart and forming a grill for contining the mass between them, the ends of the bars being severable to conform to the sidewise spacing the rails.

7. A substantially rectangular frame for retaining a filter unit, comprising: a pair of mating 'frame-sections having rails at opposite sides of the frame, respectively, a series of cross-bars having one end fixedly secured to one of the rails, a second series of cross-bars having one of their endssecured to the opposite side-rail, and means including detachably intertitting convex and concave `elements between the opposite ends of the bars oteach series and the adjacent rails for securing the rails'variably spaced'apart sidewise conformably to media of different widths, said -bars being spaced apart transversely-and vforming a grill for confining the medium between them.

#8. A substantially rectangular. retaining frame for an air filter-medium, comprising: a pair of mating framesections including rails at opposite sides of the frame, respectively, having sockets therein, a series of cross-bars having one end xedly secured to one of the rails, a second series of crosssbars having one of their ends secured to the opposite side-rail, and means including integral 1bulges between opposite ends of the bars of each series and said sockets, in the adjacent rails, for detachably and extensibly connecting the rails spaced apart sidewise conformably to media :of diierent widths, the bars being transversely spaced apart and forming a grill for contining the medium between them.

9. A substantially rectangular retaining frame for an air lter-medium, comprising: a pair of mating framesections including rails at opposite sides of the frame, respectively, having sockets therein, a series of crosslbars having one end tixedly secured to one of the rails, a second series yof cross-bars having one of their ends secured to the opposite side-rail, and means including integral bulges between opposite ends of the bars of each series and said sockets, in the adjacent rails, said bulges and sockets having wedge-engagement for detachably and extensibly connecting the rails spaced apart sidewise conformably to media of different widths, the bars being transversely spaced apart and forming a grill for conning the medium between them.

10. A substantially rectangular frame for retaining a lter-unt, comprising: a pair of mating frame-sections having rails at opposite sides of the frame, respectively, a series of cross-bars having one end xedly secured to one of the rails, a second series of cross-:bars having one of their ends secured to the opposite side-rail, and means including detachably interitting wedge-elements lbetween the opposite ends of the bars of each series and the adjacent rails for securing the rails variably spaced apart sidewise conformably to media of different widths, said bars being spaced apart and forming a grill for transversely conning the medium between them.

11. A substantially rectangular frame for retaining a lter-unit, comprising: a pair of mating frame-sections having rails at opposite sides of the frame, respectively, a series of cross-bars having one end xedly secured to one of the rai-ls, a second series of crossJbars having one of their ends secured to the opposite side-rail, and means including detachably intertting wedge-elements fbetween the opposite ends of the bars of each series and the adjacent rails for securing the rails variably spaced apart sidewise conformably to media of different Widths, said bars being spaced apart and forming a grill for transversely conning the medium between them, the ibars being formed of plastic material and severable at the wedges to remove ends thereof projecting from the side-rails.

l2. A rectangular frame for retaining a lter-mass, comprising: a pair of mating frame-sections including rails at opposite sides of the frame, respectively, of angular cross-section with outer side and cross-sectional anges, a series of cross-bars having one end xedly secured to the inward ange of one of the rails, a second `series of cross-bars having one of their ends secured to the inward ange of the opposite side-rail, the crossanges being on 'opposite faces of the frame and the outer side ilanges extending in opposite directions transversely,

and detachably intertting means between the opposite ends of the bars of each series and the opposite edges of the outer side anges of adjacent rails, respectively, for securing the rails spaced apart sidewise conformably to masses of different widths, the bars being transversely spaced apart to form a grill for confining the mass between them, the ends of the bars being severable to conform to the sidewise spacing of the rails.

13. A rectangular retaining-frame for an air iltermedium, comprising: a pair of mating frame-sections having side-rails of angular cross-section with outer side and inward anges at opposite sides of the frame, a series of cross-bar having one end Xedly secured to one of the rails, a second series of cross-bars having one of their ends secured to the opposite side-rail, and interttting means between the opposite ends of the cross-bars of each series and the outer side flanges of adjacent rails, respectively, for variably securing the rails spaced apart sidewise to encase media of different Widths, the bars being transversely spaced apart to form a grill for retaining the medium between them.

14. A rectangular retaining-frame for an air filtermediurn, comprising; a pair of mating frame-sections having side-rails of angular cross-section with outer side and inward anges at opposite sides of the frame, a series of cross-bars having one end fxedly secured to one of the rails, a second series of cross-bars having one of their ends secured to the opposite sideerail, and interitting means between the opposite ends of the cross-bars of each series and the outer side anges of adjacent rails, repectively, for variably securing the rails spaced apart sidewise to encase media of different widths, the bars being transversely spaced apart to form a grill for retaining the medium between them, the sections being formed of plastic material, the ends of the rails being severable to conform the sections for frames of different lengths.

15. A substantially rectangular retaining-frame for an air filter-medium, comprising: a pair of mating framesections having side-rails of angular cross-section with outer side and inward llanges at opposite sides of the frames, a series of cross-bars having one end xedly secured to one of the rails, a second series of cross-bars having one of their ends secured to the opposite side-rail, and intertting means between the opposite ends of the cross-bars of each series and the outer side flanges of adjacent rails, respectively, for variably securing the rails spaced apart sidewise to encase media of different widths, the bars being transversely spaced apart to form a grill for retaining the medium between them, the sections being formed of plastic material, the ends of the rails and the cross-bars being severable to conform to frames of diierent length and width.

References Cited in the le of this patent UNITED STATES PATENTS 2,118,271 Slayter May 24, 1938 2,175,903 Lichtman Oct. 10, 1939 2,393,419 Schaaf Jan. 22, 1946 2,664,172 Buttereld Dec. 29, 1953 2,789,663 Camp Apr. 23, 1957 

